Black robin record likely

Press, 27 December 1985, Page 5

Black robin record likely

FRANCES ROSS

By

of NZPA Wellington The Chatham Island black robins look likely to set new breeding records this season in spite of a late start, says a Wildlife Service team just returned from the Chathams. A Wildlife officer, Mr Don Merton, in charge of ' the black robin project, said that this summer was likely to be the robin’s most productive season.

“This year it has all come together,” he said. “All the experience and expertise we have developed over the last few breeding seasons have enabled us to fine-tune our management of the

birds so that we get the maximum number of chicks through. “There will probably be about 40 black robins by the end of summer. Considering we had only five in 1980, that is a very healthy population.” The robins were late in starting to nest, probably because damage to the bush caused by a particularly severe winter storm lessened the amount of food available. Several robins also disappeared during the storm, and at the start of the breeding season only 26 could be found. At the end of last summer there were 38.

The storm also created

difficulties for the crossfostering programme which has been responsible for the robin’s recovery. Up to a third of the Chatham Island tits, used as foster parents for robin eggs and chicks, were wiped out and those remaining were slow to nest.

“There were a few sleepless nights thinking about what to do with the robin eggs,” Mr Merton said. “But by synchronising hatching between tits and robins and combining clutches so that robin parents raised four nestlings instead of maybe two, we managed.” Combining clutches also alleviated another problem. This season some af the

tit-raised robins from previous seasons confirmed that imprinting had occurred when they mated with tits rather than other robins.

The offending birds have since been transferred from South-East Island to Mangere Island, where there are no tits, and at least one has remated with a robin.

All this season’s chicks have been transferred to robin nests before fledging, which should have them growing up under no illusions about their heritage. “All this season’s chicks will be robin-raised,” said Mr Merton.

“Although imprinting inhibits breeding, this season

has shown it can be circumvented,” he said. The Wildlife team, some of whom have been in the Chathams for nearly three months, also enclosed all the nests in specially designed nestboxes to reduce accidental losses. ,

Mr Merton is returning after New Year, to see out the end of the season.

“We hope for up to 20 young,” he said. '‘Barring catastrophes, this will be our last season of such intensive input. “The next step is to etab-’ lish the robins on the third island. Having three separate populations spreads the risk and offers a greater chance of ensuring the robinji survival.